What is the Velocity of the Second Ship Relative to the First Ship?

[jwxie]

Homework Statement

Two ships, one moving 15 degree west of north with a speed 25 mi/h., the second moving 25 degree south of west with a speed 20 mi/h. relative to water pass each other. Find the velocity of the second ship relative to the first ship (magnitude and direction).

Homework Equations

V1 + r = V2
V2 - V1 = r

The Attempt at a Solution

I want to confirm on this.

My approach is using this relation.
V1 + r = V2
and so V2 - V1 = r, where r is the velocity we are looking for of our problem.

Then I will take components, x and y, and find sqrt(x^2+y^2) and direction tan-1 y/x

 

[tiny-tim]

Hi jwxie!

(have a square-root: √ and try using the X² and X₂ tags just above the Reply box )

My approach is using this relation.
V1 + r = V2
and so V2 - V1 = r, where r is the velocity we are looking for of our problem.

Then I will take components, x and y, and find sqrt(x^2+y^2) and direction tan-1 y/x

Yes, that's exactly right!

(btw, I wouldn't use r, I'd stick to the same area of the alphabet, and use v₁₂ or u or w )

 

[jwxie]

Hi, tiny, thank you for your confirmation. My friend had an exam and he doubted about my explanation. Thank you!

I will make sure I check all the synatx ^^